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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A total of 17,130 children of both sexes born in 1964 and living in Hungary, USSR, GDR and Cuba were examined in 1977. The children were grouped in upper (U) and lower (L) blood pressure groups and 3,640 children were re-examined in 1978-1981. The parents' age, smoking habits, marital status, the children's order of birth, number of siblings, and proportion of twins did not differ between U and L. The prevalence of hypertension and diabetes in the medical history of the children, and the prevalence of hypertension and stroke and diabetes in the medical history of the parents were significantly higher in U than in L. Signs of left ventricular hypertrophy and systolic murmurs, the magnitude of R and S waves in the ECG, and mean values of cardiothoracic and heart volume indices were higher in U than in L. Children in U were sexually more developed, taller, more obese (greater Quetelet's index and skinfold thickness) and less active physically. Average values of blood sugar and serum uric acid were also higher in U than in L. No difference was found between the two groups in the proportion of smokers and in mean cholesterol values. These differences between U and L were strengthened in comparison of children who showed repeatedly low (below the 30th percentile) or high (at or above the 70th, 90th and 95th percentile) readings in the SBP and DBP distribution curves. Since we did not find important differences when we related various factors to blood pressure taken on one or two separate occasions we emphasize the importance of casual blood pressure measurement in childhood.
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PMID:Blood pressure in childhood and adolescence. Results from an international collaborative study on juvenile hypertension. 387 90

The following summary of the physiologic and epidemiologic evidence may help the clinician in making decisions when caring for persons with ISH: ISH is predominantly found in older age groups, being present in 1% to 4% of the population under age 40, 10% to 15% between ages 60 and 70, and 25% to 30% over age 70. ISH is more prevalent in women than in men. The development of ISH in the aged is associated with a decrease in arterial compliance. The relationship whereby ISH is both a cause and a result of atherosclerotic vessels needs further delineation. Neurohumoral factors also have a part in determining arterial compliance. An elevated SBP is an important contributor to the risk of developing coronary artery disease, and in persons over 45 years old it is a more powerful predictor of coronary events than DBP. SBP is a better discriminator of risk for strokes at all ages than DBP is. The relative risk in persons with ISH for the development of coronary artery disease and stroke is two to five times that of normotensive persons, but is no worse than the risk for these events among treated hypertensives. Although the relative risk of ISH is not strikingly large, the high prevalence of ISH among aged individuals, the increasing size of the population over 65 years old, and the high incidence rate of cardiovascular events in the aged give ISH a sizable attributable risk in the population (13 to 28 deaths per 1,000 individuals). It remains to be shown that lowering SBP in ISH removes the risk of ISH. Studies are needed that monitor the costs and adverse effects of therapy as well as the possible benefits when a condition such as ISH is most commonly seen in the aged.
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PMID:Isolated systolic hypertension: how common? How risky? 389 52

A prospective longitudinal study of black medical students was conducted to determine the predictive value of hypertension precursors. Follow-up examinations, averaging 22.5 years later, were performed on 341 subjects (78.8%); 25 (5.8%) additional subjects were identified as dead out of 433 original participants. Results are reported on 313 reexamined men. A remarkable 43.8% of the physicians had elevated blood pressure higher than 140/90 mm Hg or gave a history of hypertension and treatment. Correlation coefficients, quintile distributions, and regressions all confirmed the ability of baseline SBP and DBP to predict their respective pressures on follow-up examination. Discriminant function tests yielded baseline SBP, DBP, smoking, and parental history of stroke or hypertension to be the most significant precursors distinguishing hypertensive from normotensive groups, and the model correctly classified 69.7% of the subjects. Baseline cholesterol and Quetelet index levels did not reach statistical significance. The cold pressor test was not predictive but interim weight gain was highly significant. Results are discussed in relation to comparable studies on white populations.
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PMID:Risk factors and the incidence of hypertension in black physicians: the Meharry Cohort Study. 403 89

We examined echocardiographically in a single-blind crossover trial the circulatory effects of an inhaled selective beta 2-adrenergic bronchodilator, fenoterol. Eight healthy subjects were studied on the first and fourteenth day after randomly assigned therapy with either no drug or 400 micrograms fenoterol by metered dose inhaler four times a day. Heart rate (HR) and systolic (SBP) and diastolic (DBP) blood pressure responses to fenoterol were small (means +/- SE; HR: +4 +/- 1.3 bpm; SBP: +6 +/- 1.3 mm Hg; DBP: -3 +/- 1.4 mm Hg). In contrast, mean cardiac output increased 26% (1.1 +/- 0.2 l/min), accompanied by an 18% fall in total peripheral vascular resistance (-6 +/- 1.3 U), a 16% increase in stroke volume (+12 +/- 2.5 ml), and an 18% increase in the mean velocity of circumferential shortening (+0.2 +/- 0.04 c/s). Responses varied widely among subjects; maximum observed increase in cardiac output was 117% (+5.48 l/min) in one subject. There was no evidence to suggest development of tolerance to these hemodynamic effects, as the response of measured variables did not differ after 2 wk of regular fenoterol therapy. We conclude that selective beta 2-bronchodilators are not without potential for hemodynamically significant effects when taken by metered inhalers in recommended therapeutic doses and that the magnitude of such effects is underestimated when measured by HR and blood pressure changes.
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PMID:Hemodynamic effects of an inhaled beta-2 agonist. 673 28

In 1979, a community-wide hospital surveillance system was established in Monroe County, New York (population 702,000), to investigate the continuing contribution of uncontrolled high blood pressure (HBP) to the occurrence of stroke. This paper reports findings among 200 consecutive strokes in persons under 71 years of age. Average age was 58. There was a prestroke history of HBP in 129 (65 per cent) cases. Two-thirds of the 129 had other predisposing conditions (heart disease, diabetes, previous cerebrovascular accident) and 95 per cent had one or more other cardiovascular risk factors (smoking, elevated cholesterol, obesity). Over 90 per cent had visited a physician during the year prior to stroke (average of four visits). Elevated pressures (DBP greater than or equal to 95 or SBP greater than or equal to 160) were recorded at half or more of the visits for 45 per cent of the patients; these cases were classified as uncontrolled. Reduction of "unnecessary" strokes in persons under age 71 should be achievable by giving increased attention to those already under medical care for hypertension who have co-existing stroke risk conditions and cardiovascular risk factors.
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PMID:Community surveillance of stroke in persons under 70 years old: contribution of uncontrolled hypertension. 682 12

This was an echocardiographic study of the cardiovascular effects of prostacyclin (PGI2) infused intravenously to human volunteers at the rate of 20 ng . kg-1 . min-1 for 10 minutes. The following parameters were recorded in the steady state, at one-minute intervals throughout infusion and the ensuing recovery period: systolic, diastolic, and mean blood pressure (SBP, DBP, MBP); heart rate (HR); left ventricle end-diastolic (EDD) and end-systolic diameter (ESD); stroke volume index (SVI); cardiac index (CI); peripheral vascular resistance (PVR); left ventricle fractional shortening (FS) and ejection fraction (EF). We detected a progressive reduction of MBP without any HR modification. MBP reduction was associated with a reduction of PVR and a parallel rise of CI and SVI. There was also an increase of FS and EF reflecting a reduced ESD. We conclude that PGI2 infused in man at the rate stated above causes hypotension reflecting an arterial vasodilating effect; a lack of heart rate reflex response to afterload reduction (probably a nerve-mediated effect of PGI2); and no venous vasodilation, judging from the absence of any change in end-diastolic diameter.
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PMID:Prostacyclin effect on cardiovascular system in man evaluated by echocardiography. 703 23

The cardiac hemodynamic effects of bimakalim, a new potassium channel opener, were evaluated in 12 normal volunteers by echocardiography (ECHO)/Doppler in a placebo-controlled, randomized double-blind, cross-over, dose-ranging study. A single oral dose (0.25-1 mg) was given at weekly intervals. Hemodynamic measurements were made at 0, 90, 120, and 240 min after drug intake and ECHO/Doppler was performed at 0 and 90 min. Reproducibility of the ECHO/Doppler study was assessed by comparing predose baseline values of the four different phases of treatment (placebo and 0.25, 0.5, and 1 mg) by analysis of variance (ANOVA), which showed no significant differences for left ventricular ejection fraction (LVEF). Doppler-derived stroke volume (SV), total peripheral resistance (TPR), and peak mitral early to late velocity ratio (PEV/PAV). ANOVA showed significant increases in LVEF (p = 0.0003) and SV (p = 0.03), however, and decreases in TPR (p = 0.002) and PEV/PAV (p = 0.005) after bimakalim treatment. Heart rate (HR) showed a dose-dependent increase, but systolic and diastolic blood pressure (SBP, DBP) did not change with bimakalim. Despite vasodilatory headaches, none of the volunteers discontinued the study. Bimakalim appears to be a potent vasodilating drug that may have an important role in management of patients with compromised LV function.
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PMID:Potent hemodynamic effects of bimakalim, a new potassium channel opener, in humans. 750 24

Epidemiological data suggest that the lower the BP, the lower the cardiovascular risk. This is true across a broad range of BP levels, including those considered 'normal'; more than half of all cardiovascular events attributed to raised BP occur when DBP is < or = 95 mmHg. The belief that lowering BP too far is harmful is based on the hypothesis of a J-shaped relationship between BP and risk of cardiovascular disease. The weight of evidence now clearly suggests, however, that the J-shaped curve is not a consequence of treatment, but of underlying cardiovascular dysfunction that reduces BP and increases morbidity and mortality. Current prospective observational data give no evidence of a threshold BP below which there is no further reduction in cardiovascular disease risk. The average BP reductions in randomised trials are 5-6 mmHg (diastolic) and 10-12 mmHg (systolic), which would be expected to reduce the incidence of stroke by 35% and of coronary heart disease by 21%. If average BP reductions were doubled, prospective observational studies suggest the cardiovascular risk would be reduced by a further 15-20%.
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PMID:What are the implications for the community of the discrepancy between the theory and practice of BP control? 756 94

Prospective observational studies show clearly that the risks of stroke, coronary heart disease and premature death are related directly to BP. Furthermore, the results of prospective, randomised intervention studies indicate that effective BP control reduces these risks. Although the number of patients being treated for hypertension has approximately doubled in the last 20 years, premature morbidity and mortality remain higher than in the normotensive population. This may relate to the inadequate level of BP control achieved in many patients. Two large studies have shown that DBP can be reduced to < 90 mmHg in almost all patients if antihypertensive therapy is intensified, and preliminary evidence suggests that this can be done without increasing the incidence of side-effects. The level to which BP should be reduced to achieve an optimum reduction in cardiovascular morbidity and mortality is currently being investigated in the Hypertension Optimal Treatment (HOT) Study.
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PMID:The hidden truth: what do the clinical trials really tell us about BP control? 756 96

Effects of four intravenous (i.v.) doses (0.25, 0.5, 1, and 2 micrograms/kg) of the alpha 2-adrenoceptor agonist clonidine (CLO) were studied in 7 normotensive male volunteers in a placebo-controlled double-blind randomized design to evaluate the role of alpha 2-adrenoceptors in spontaneous short-term cardiovascular fluctuations. Heart rate (HR), systolic and diastolic blood pressure (SBP, DBP; Finapres device), stroke volume (SV) and total peripheral resistance (TPR) were monitored for 1 h after infusion of CLO while the subjects rested in a semirecumbent position. For HR, SBP, and DBP, power spectra and variation coefficients were calculated for consecutive time segments of 2.5 min. Power density was assessed for three frequency bands: low (LFB, 0.02-0.06 Hz), mid (MFB, 0.07-0.14 Hz), and high (HFB, 0.15-0.40 Hz). Per time-segment, baroreflex sensitivity (BRS) was estimated as the gain (or modulus) in MFB between systolic pressure values and R-R interval times. Decreases in mean levels of SBP and DBP were observed within 15 min after infusion of > or = 0.5 micrograms/kg CLO. HR first showed a slight increase 15 min after infusion of 0.5, 1, and 2 micrograms/kg CLO, but decreased subsequently as in all doses, including placebo. SV and TPR decreased after a dose of 2 micrograms/kg CLO. LFB and MFB power of HR were reduced after 2 micrograms/kg CLO, but only during the first 30 min after infusion; during this period, respiratory depth was also diminished, indicating that these effects may reflect a reduction in sympathetic outflow as well as a reduction in vagal outflow.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cardiovascular variability after clonidine challenge: assessment of dose-dependent temporal effects by means of spectral analysis. 769 82


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